Refrigerating apparatus



P. J. MACDONALD.

REFRIGERATING APPARATUS.

(No Model.)

Patented June 3, 1890,

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UNITED STATES PATENT OFFICE.

PETER J. MACDONALD, OF BOSTON, MASSACHUSETTS.

REFRIGERATING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 429,198, dated June 3, 1890.

Application filed May 18, 1889.

To all whom, it may concern:

Be it known that 1, PETER J. MACDONALD, of Boston, county of Suffolk, State of Massachusetts, have invented certain new and usefullmprovementsinRefrigei-ating Apparatus, of which the following is a specification, reference being had to the drawing accompanying and forming a part hereof, in which I have shown an elevation of my apparatus partially in section for greater clearness.

My invention relates to that class of apparatus in which the refrigeration is obtained by the expansion of gas.

The object. of my present invention is the construction of an improved apparatus by which a pure and dry gas may be obtained with a minimum wastage and pressure; and it consists in the peculiar construction and arrangement of the apparatus, as hereinafter described and claimed, as also in the employment therewith of a drip-chamber, whereby steam or moisture which may pass out of the gas-generating chamber with the gas will be condensed and separated from the gas and returned directly to the gas-generating chamher, as hereinafter set forth.

In my apparatus I use ammonia, and by the use of the improvements herein set forth I obtain the two effects which are most desired in an apparatus of this kindviz., the production of the driest gas in the pipes and of the purest waterin the gas-generatin g-chamberthat is, the ammonia in the driest form is most thoroughly and completely driven out of the watery solution in 'the gas-generating chamber.

My invention is simple and Will be readily understood from the following description, in which reference is made to the accompanying drawing.

A represents a boiler, which may be of any desirable form, and which is arranged with a furnace underneath, the grate-bars of which are shown at B. One or more fines to pass from the fire box or chamber up through the boiler.

Inside the boiler A, I arrange a chamber D, having pipes b to accommodate the fiues a, and somewhat larger than the flues, so that there will be a column of water surrounding the fines. The chamber D receives the am- Serial No. 311,277. (No model.)

aqua-ammonia, the strength of which may vary, but which contains usually about twenty-six per cent. of ammonia. The inlet to this chamber may be arranged in any suitable way. In the drawing it is shown at c, and the inletto the boiler may also be in any well-known form. i

A safety-valve is shown at d.

A pipe f passes from the gas-generating chamber D, being bent on itself, preferably, substantially in the form shown, and having connected with it the drip-chamberE. From the drip-chamber the pipe passes upwardly, and thence to the receiver H, into which it discharges.

Above the drip-chamber E the pipe f is surrounded by a sleeve 9, having a funnelshaped top to receive the water which may be poured or run into it, and having an outlet-pipe h to allow of the discharge of the water. This device is a dehydrator and is for the purpose of allowing a column of cold running water to be kept constantly around a portion of the pipe f. A similar device is provided on the pipe f just above the receiver H, as shown at j, which may be used, if desired, and by which a stream of cold water may be kept constantly flowing around that portion of the pipe f. A faucet is provided in the pipe f at 70, near the ammonia-chamher, by which the pipe may be closed when it is desired to cut off the escape of the gas from the chamber. A similar faucet is provided for closing the pipe at 1, near the receiver H. a

From the receiver a pipe m passes to the refrigerating-chamber J, where=it is bent in a series of coils n, and thence p'assesback in the'manner shown to the cylinder 1) of a pump, which acts to force any ammonia which may pass through the pipe on back into the gasgenerating chamber D. The steam-cylinder of the pump is shown at q, and the pump is operated in any well-known manner, preferably by steam from the boiler. By this arrangement the ammonia which passes from the receiver through the refrigerating-chamber is pumped back into the gas-generating chamber within the boiler.

The drip-chamber E is connected with the monia, which is placed therein in the form of I pipe f by a connectingpipe which is provided with a faucet =2, a similar faucet being provided below the drip-chamber in the pipe .9, which leads from the drip-chamber to the return-pipe m, as shown.

The drip-chamber is provided with a glass gage t to indicate the amount of liquid within it.

A pressure-gage it is provided on the receiver II to indicate the amount of pressure therein, and a gage 10, similar to that on the drip-chamber, is also provided on the receiver to indicate the amount of liquid therein. The return-pipe m is also provided with a funnelshaped inlet 3 provided with a suitable stopcock, by means of which that portion of the pipe on may also be filled with aqua-ammonia, so as to serve as an additional receptacle to the gas-generating chamber D. By making this portion of the pipe m long enough a very large quantity of aqua ammonia may be stored, which will be pumped into the chamber D as the solution in the chamber is exhausted, so that the same result is obtained as if the chamber D were made very much larger.

The operation of the device is as follows: \Vatcr being placed in the boilerA and aquaammonia in the chamber D, the stop-cock 7c is opened and a slowfire is placed in the furnace beneath the boiler, and as the water in the boiler heats gas is generated in the chamber D and passes through the pi pe f to the receiver II, the stopcock at a in the pipe m,which leads from the compressor, being closed. In this way the receiver is charged with dry gas while the temperature of the boiler is still low. \Vhen the pressure in the receiver is sufficient, at which time the gas therein will be liquefied, the stopcock :0 is partially opened and the gas is allowed to pass through the pipe at in the refrigerating-e11amber. As the ammonia in the chamber D becomes exhausted and the heatincreases, some moisture in the form of steam or vapor is liable to pass with the ammonia into the pipe f. To condense this vapor and prevent it passing over with the am monia-gas, a stream of cold water is run through the jacket. (Shown at g.) This operates to condense the Watery vapor, which after condensation, passes down into the dripchamber E, the stop-cock at 7 being open. As this water I vapor passes into the dripchamber E, it will probably take a small percentage of ammonia with it. Vhen the dripchamber has been filled in this way, (the stop-cock below the chamber at r in the pipe .9 being shut,) the stop-cock r is closed and the stopcock r is opened. The opening of the stop-cock '1" allows the liquid in the dripchamber to pass down through the pipe 8 into the return-pipe m, and thence to be pumped back again through the pump-cylinder 1) into the chamberD with the exhausted gas, which passes from the refrigeratingchamber in the return-pipe m. After the drip-chamber has been emptied in this way the stop-cock at r is again closed and that at 7' opened, and the operation repeated.

I have shown the receiver II as surrounded by a receptacle 2', which may contain cold water or brine. This receptacle I do not consider necessary, although I prefer to use it.

A check-valve of any well-known form may be inserted in the return-pipe m to prevent the gas in said pipe from going toward the refrigerating-chamber. Such a check-valve is indicated at b.

It will be obvious that the extent of the pipe f, which is surrounded by the cold-water Jackets 9 and j, may be varied as desired.

By the use of the drip-chamber E all of the gas which passes into the receiver, whether under a high or a low heat, and whether the ammonia in the chamber D is nearly exhausted or not, is kept dry, while the wastage is reduced to the minimum.

Reference is herein made to my application, Serial No. 312,9l7, which shows and describes a refrigerating apparatus similar in general construction to that above described.

\Vhat I claim is- A refrigerating apparatus consisting of a gas-generating chamber, an outlet-pipe therefrom, a receiver connected with said pipe, a refrigeratirig-chamber, and a pipe leading from said receiver to said refrigerating-chamber and thence back to the said gas generating chamber therefor, in combination with a drip, adehydrator and chamber connected with the outlet-pipe from the gas-generating chamber, said drip-chamber being provided with a discharge-pipe directly connected with the return-pipe from the refrigeratirig-chamber, for the purpose and substantially as shown and described. 1

PETER J. MACDONALD. \Vitnesses:

WM. A. MACLEOD, ROBERT WALLACE. 

